Chess Traps | Slav Defence
The Slav Defense is a chess opening that begins with the moves:
1. d4 d5
2. c4 c6
The Slav is one of the primary defences to the Queen's Gambit. Although it was analyzed as early as 1590, it was not until the 1920s that it started to be explored extensively. Many masters of Slavic descent helped develop the theory of this opening, including Alapin, Alekhine, Bogoljubov, and Vidmar.
The Slav received an exhaustive test during the two Alekhine–Euwe World Championship matches in 1935 and 1937. Played by 11 of the first 13 world champions, this defence was particularly favoured by Euwe, Botvinnik, and Smyslov. More recently the Slav has been adopted by Anand, Ivanchuk, Lautier, Short, and other top grandmasters, including use in six of the eight games that Vladimir Kramnik played as Black in the 2006 World Championship (in the other two, he played the related Semi-Slav Defense).
Today the theory of the Slav is very extensive and well-developed.
There are three main variations of the Slav:
The "Pure" Slav or Main Line Slav where Black attempts to develop the light-squared bishop to f5 or g4.
The a6 Slav or Chebanenko Slav with 4...a6.
The Semi-Slav with ...e6 (without developing the light-squared bishop). The Semi-Slav Defense, a kind of a combination Queen's Gambit Declined and Slav Defense is a very complex opening in its own right.
There is also a lesser option, the Schlechter Slav with ...g
Black faces two major problems in many variations of the Queen's Gambit Declined (QGD):
Development of his queen bishop is difficult, as it is often blocked by a black pawn on e6.
2. The pawn structure offers White targets, especially the possibility of a minority attack on the queenside in the QGD Exchange Variation.
The "Pure" Slav and a6 Slav addresses these problems. Black's queen bishop is unblocked; the pawn structure remains balanced. Also, if Black later takes the gambit pawn with ...dxc4, the support provided by the pawn on c6 (and possibly ...a6) allows ...b5 which may threaten to keep the pawn or drive away a white piece that has captured it, gaining Black a tempo for queenside expansion. On the other hand, Black usually will not be able to develop the queen bishop without first giving up the centre with ...dxc4, developing the bishop may leave the black queenside weak, and the thematic break ...c5 incurs the loss of a tempo.
The Slav can be entered by many move orders. The possibilities include 1.d4 d5 2.Nf3 Nf6 3.c4 c6, 1.Nf3 d5 2.c4 c6 3.d4 Nf6, and so on.
Alternatives to 3.Nf3
The mainline is 3.Nf3. White can also try the following alternatives:
Black often plays 3...Nf6 but 3...Bf5 is considered to be an easier equalizer. Also, 3...Nf6 4.Nc3 (same as 3.Nc3 Nf6 4.e3 below) may give Black some move-order issues for those wanting to play the "Pure" Slav and not the semi-slav or ...a6 Slav.
Exchange Slav: 3.cxd5
The Exchange Variation was once described as "the system that takes the fun out of playing the Slav" for Black. After 3.cxd5 cxd5, the symmetrical position offers White only the advantage of the extra move, but the drawish position offers Black little chance to win unless White is overly ambitious. The rooks will often be exchanged down the now open c-file. This line is often used as a drawing weapon and if both players want to draw, they can play the symmetrical line, which continues 3... cxd5 4.Nf3 Nf6 5. Nc3 Nc6 6. Bf4 Bf5, where the position is totally symmetrical and every piece is developed to a good square. This has an 84% draw percentage according to the Chess.com database and is one of the most drawish lines in chess, especially after 7. e3 e6 8. Bd3 (after Bd3, there is 97% drawing chance, according to previous games). To avoid this possibility Black often chooses the move order 2...e6 followed by 3...c6 to enter the Semi-Slav.
The pressure on Black's centre prevents 3...Bf5? since after 4.cxd5 cxd5 5.Qb3 White wins a pawn. Black can try the Winawer Countergambit, 3...e5, which was introduced in Marshall–Winawer, Monte Carlo 1901 but this is thought to be slightly better for White. The most common continuation is 3...Nf6 when 4.Nf3 transposes to the mainline. White can also play 4.e3 when it was thought Black could no longer play the "Pure" Slav with 4...Bf5 (and had to choose between 4...e6 or 4...a6) due to 5.cxd5 cxd5 6.Qb3. Therefore, "Pure" Slav players sometimes meet 3.Nc3 with 3...dxc4, the Argentinian Defense, which can transpose to the mainline of the "Pure" Slav. Recently the Gambit 4...Bf5 5.cxd5 cxd5 6.Qb3 Nc6 7.Qxb7 Bd7 has revitalized 4...Bf5.